Conventionally, glass plates are used in various fields. In particular, glass plates (also referred to as glass substrates) for use with liquid crystal displays, plasma displays, etc are very thin. The glass plates with a thickness of about 0.7 mm and a size of about 550 mm×650 mm are often manufactured. The glass substrate is typically conveyed in a horizontal position (lying position) by a belt conveyor or the like and is subjected to processing such as trimming or venting in the horizontal position in the respective devices (see for example, Japanese Laid-Open Patent Application Publication No. Hei. 8-59269).
In addition, there has been disclosed an apparatus that conveys the glass plate in a substantially upright position, leaning against roller trains, and, in this state grinds each of the edges of the glass plate (see e.g., Japanese Patent Publication No. 2623476). These apparatuses are fixedly mounted to an installation floor surface.
In recent years, in fields of glass substrates and so on, there has been a need for larger-sized glasses so that a yield increases for improved productivity or the glasses are incorporated into larger displays and so on. In addition, there has been a need for improved transportability of displays and so on by thinning the glass substrate. So, the present trend is toward the production of thinner glasses. Furthermore, there have been increasing demands for a higher quality and for a lower cost of the glass substrates.
In the technique for conveying and processing the glass plate in the horizontal position and in the technique for processing the glass plate in the substantially upright position, leaning against some structural members, the larger and thinner glass plate may be broken due to deflection because of its own weight, or due to a reactive force applied from the structural members that convey the glass plate while supporting the surface thereof, when it is processed. The larger glass plate horizontally laid causes an increase in an installation area of the apparatus, and an increase in the size of the apparatus, resulting in an increased cost. In addition, maintenance becomes difficult because of an increase in a width of the apparatus. Moreover, in the system in which processing units or washing units are fixedly mounted, it is difficult to change the line quickly depending on how the plate material is processed.